Method of and device for abrasive machining and abrasive tool provided therefor

ABSTRACT

Fine abrasive machining of a part includes providing a tool having a plurality of successive portions configured and arranged so that each preceding portion provides a coarser abrasive machining while each subsequent portion provides a final abrasive machining, and providing a relative movement of the abrasive tool relative to the part so that first a portion of the tool configured a coarser abrasive machining machines a part and thereafter a portion of the tool configured for a finer machine provides abrasive machining of the part.

BACKGROUND OF THE INVENTION

The present invention relates to a method of and a device for fineabrasive machining of materials, and also to all abrasive tool providedtherefor.

Methods and devices for all abrasive machining, and abrasive tools forthem are well known in the art. In known machining processes andequipment in order to provide a fine finished surface an abrasivemachining is performed by multiple instruments and means, which carryout successive processes of removing the material from a workpiece in away that a coarser machining is performed in preceding processes while afiner machining is performed in subsequent processes. For example, forfine abrasive machining of a glass surface, for example three spindleswhich carry abrasive grinding tools are first used; then, for examplethree further spindles with abrasive tools for prepolishinig machiningare used; and then three tools with abrasive polishing slurry areutilized. Substantially similar processes, tools and equipment are usedfor fine abrasive machining of other materials.

With the above described known abrasive machining, a significant numberof tools with a complicated equipment and multi-step processes areutilized, which are characterized by increased cost of instruments andequipment, size of equipment, and time of machining.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide amethod of and a device for fine abrasive machining of materials, and anabrasive tool provided therefor, which are further improvements of theexisting methods, devices and tools.

In keeping with these objects and with others it should become apparenthereinafter, one feature of the present invention resides, brieflystated, in a method of fine abrasive machining of a part, comprising thesteps of providing a tool having a plurality of successive portionsconfigured and arranged so that each preceding portion provides acoarser abrasive machining while each subsequent portion provides afiner abrasive machining; and providing a relative movement of theabrasive tool relative to the part so that first a portion of the toolconfigured for a coarser abrasive machining machines a part andthereafter a portion of the tool configured for a finer machiningprovides abrasive machining of the part.

It is another object of the present invention to provide a device forabrasive machining of a part, comprising a tool having a plurality ofsuccessive portions configured and arranged so that each precedingportion provides a coarser abrasive machining while each subsequentportion provides a finer abrasive machining; and means providing arelative movement of the abrasive tool relative to the part so thatfirst a portion of the tool configured for a coarser abrasive machiningmachines a part and thereafter a portion of the tool configured for afiner machining provides abrasive machining of the part.

It is still a further object of the present invention to provide anabrasive tool for fine abrasive machining of a part, the tool having aplurality of successive portions configured and arranged so that eachpreceding portion provides a coarser abrasive machining while eachsubsequent portion provides a finer abrasive machining, so that with arelative movement of the abrasive tool relative to the part first aportion of the tool configured for a coarser abrasive machining machinesa part and thereafter a portion of the tool configured for a finermachining provides abrasive machining of the part.

When the method of abrasive machining is performed, the device forabrasive machining is designed, and an abrasive tool is configured inaccordance with the present invention, instead of a multiple equipment amultiple step operation, a single abrasive tool can be used for abrasivemachining starting from a coarse machining and proceeding until a finalmachining of the part.

In accordance with another feature of the present invention, a workingsurface of the abrasive tool used in the inventive method and in theinventive device, can be inclined, and also a tool can be configured asa rotary tool with an axis of rotation which is inclined as well, so asto provide the above mentioned abrasive machining of parts.

The novel features which are considered as characteristic for thepresent invention are set forth in particular in the appended claims.The invention itself, however, both as to its construction and itsmethod of operation, together with additional objects and advantagesthereof, will be best understood from the following description ofspecific embodiments when read in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end, axial view of an abrasive tool in accordance with thepresent invention, for use in an inventive method of fine abrasivemachining and in an inventive device for fine abrasive machining;

FIG. 2 is a side view showing an abrasive tool in accordance with thepresent invention;

FIG. 3 is a side view of an inventive device for fine abrasive machiningwith the use of the inventive method and the inventive abrasive tool;and

FIG. 4 is a perspective view showing another embodiment of an inventiveabrasive tool, as well as an inventive method and an inventive devicefor fine abrasive machining.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an abrasive tool in accordance with the present inventionwhich is used for fine abrasive machining in a device for fine abrasivemachining in accordance with the present invention.

An abrasive tool in accordance with the present invention has aplurality of individual portions which are identified with referencenumerals 1, 2, 3 and 4. It is to be understood that it is possible toprovide less than four portions or more than four portions, depending ona material of a part to be treated, a degree of fineness of abrasivemachining, and many other factors. The tool is formed as an integraltool including all above portions formed integrally with one another.

The portions 1, 2, 3, 4 of the tool shown in FIG. 1 are configured forproviding a different degree or fineness of abrasive machining. Thepreceding portions are provided for a coarser abrasive machining, whilesubsequent portions are provided for a finer abrasive machining.

If the fine abrasive machining is performed with the abrasive tool shownin FIG. 1, so that the abrasive machining starts by the center of thetool and proceeds toward its periphery, then the portion 4 is configuredfor the coarsest abrasive machining, while the portion 1 is configuredfor the finest abrasive machining.

For example for machining a glass parts, the portion 4 can containabrasive particles such as diamond particles with a size of 150-200micron and a concentration of 100%, the portion 2 can contain diamondparticles with a size of 80-63 micron and concentration of 75%, theportion 2 can contain diamond particles with a size of 40-28 micron anda concentration of 50%, and the portion 1 can contain diamond particleswith a size of 10-7 micron and a concentration of 25%.

It is believed to be clear that the concentration is selected inaccordance with the international standards, wherein 100% concentrationmeans that there are 72 karat in one cubic inch of the portion.

It is to be understood that both the size of the abrasive particles inthe portions 1, 2, 3, 4 as well as the concentration of the abrasiveparticles in these portions can be different, depending on a material ofa part to be treated, and other parameters of the method.

If the fine abrasive machining is performed by starting from theperiphery of the tool and progressing toward its center, theconcentration of the abrasive particles decreases in the same direction.

As shown in FIG. 1, the portions 1, 2, 3, 4 are formed as concentricportions arranged around a common center or axis A.

With the inventive tool, in the inventive method and the inventivedevice, various materials can be subjected to abrasive machining, forexample glass, ceramics, metals, ferrites, semiconductor crystals, etc.

Various abrasives can be used as abrasive particles in the correspondingportions, such as diamonds, cubic boron nitride, aluminum oxide, ceriumoxide, zirconium oxide, silicon carbide, etc.

The machining of the materials can be performed for any areas ofcorresponding parts, such as surfaces, edges, bevels, arises, etc.

In accordance with a further feature of the present invention, a workingsurface of the abrasive tool is inclined at a predetermined angle to ahorizontal plane.

As shown in FIG. 3 the inclination of the working surface of the tool isperformed with an angle α from the axis of the tool and going to itsperiphery, uniformly around the axis A.

During abrasive machining of a part, for example a glass part shown inFIG. 2, the tool is arranged so that the axis of rotation A of the toolis inclined relative to a vertical axis by an angle β so that a part ofthe working surface of the tool at one side of the axis A is for examplehorizontal (at the right side of the axis A) and is in contact with thepart to be machined, while another part of the tool is not in contactwith the part to be abrasively machined (left side of the axis A.

When as shown in FIG. 2 the part to be machined, for example a glasspart, is displaced relative to the tool or vice versa, the glass part issuccessively finely abrasively machined by the portions 4, 3, 2, 1 ofthe inventive tool, thus successively providing a coarser treatment,then a finer treatment, then a more finer treatment, and then a finalfine treatment by the corresponding portions 4, 3, 2, 1.

In the embodiment shown in FIGS. 1-3 the abrasive tool is formed as anabrasive disk with an end-side abrasive layer that include theabove-mentioned portions.

FIG. 4 shows another embodiment of the abrasive tool in accordance withthe present invention, which is used in accordance with the presentinvention in the inventive device for fine abrasive machining.

In the embodiment of FIG. 4 a centreless fine abrasive machining isperformed. For this purpose the abrasive tool is formed as a rollerhaving a plurality of disk shaped portions 5, 6, 7, 8, 9 integrallyattached to one another to form a single integral abrasive tool. A partto be machined is advanced between the abrasive tool and an oppositerotating roller so as to be successively finely machined.

Each preceding disk-shaped abrasive portion of the tool shown in FIG. 4provides a coarser abrasive machining than each subsequent abrasiveportion. The corresponding portions 5, 6, 7, 8, 9, can have a size ofabrasive particles 150-200 micron, 100-70 micron, 50-30 micron, 25-15micron, 10-7 micron, with corresponding concentrations 100%, 80%, 60%,40%, 20%.

The device for fine abrasive machining shown in FIG. 2 includes theabrasive tool described herein above, and means for rotating theabrasive tool around an axis A which are known per se in the art andformed for example as a rotatable spindle.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofmethods and constructions differing from the type described above.

While the invention has been illustrated and described as embodied in amethod of and a device for abrasive machining, and abrasive toolprovided therefor, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, be applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

1. A method of fine abrasive machining of a part, comprising the stepsof providing a tool having a plurality of successive portions configuredand arranged so that each preceding portion provides a coarser abrasivemachining while each subsequent portion provides a finer abrasivemachining; and providing a relative movement of the abrasive toolrelative to the part so that first a portion of the tool configured fora coarser abrasive machining machines a part and thereafter a portion ofthe tool configured for a finer machining provides abrasive machining ofthe part.
 2. A method as defined in claim 1; further comprising formingsaid portions of the abrasive tool as concentric portions extendingaround an axis of rotation of the abrasive tool.
 3. A method as definedin claim 1; further comprising forming said portions of the abrasivetool as abrasive disks which are arranged successively after one anotherin a direction of an axis of rotation of the abrasive tool.
 4. A methodas defined in claim 1; further comprising forming a working surface ofthe abrasive tool so that it is inclined at a predetermined angle.
 5. Amethod as defined in claim 4; further comprising inclining an axis ofrotation of said abrasive tool at a predetermined angle, so that atleast one part of the working surface of an abrasive tool extendssubstantially in correspondence with a surface to be treated.
 6. Amethod as defined in claim 1; further comprising forming the portions ofthe abrasive tool integral with one another, to form the abrasive toolas an integral tool.
 7. A device for abrasive machining of a part,comprising a tool having a plurality of successive portions configuredand arranged so that each preceding portion provides a coarser abrasivemachining while each subsequent portion provides a finer abrasivemachining; and means providing a relative movement of the abrasive toolrelative to the part so that first a portion of the tool configured fora coarser abrasive machining machines a part and thereafter a portion ofthe tool configured for a finer machining provides abrasive machining ofthe part.
 8. A device as defined in claim 7, wherein said portions theabrasive tool are formed as concentric portions extending around an axisof rotation of the abrasive tool.
 9. A device as defined in claim 7,wherein said portions of the abrasive tool are formed as abrasive diskswhich are very successively after one another in a direction of an axisof rotation of the abrasive tool.
 10. A device as defined in claim 7,wherein said abrasive tool has a working surface which is inclined at apredetermined angle.
 11. A device as defined in claim 10, wherein anaxis of rotation of said abrasive tool is inclined at a predeterminedangle, so that at least one part of a working surface of an abrasivetool can extend substantially in correspondence with a surface to betreated.
 12. A device as defined in claim 7, wherein the portions of theabrasive tool are integral with one another, so that the abrasive toolis formed as an integral tool.
 13. An abrasive tool for fine abrasivemachining of a part, the tool having a plurality of successive portionsconfigured and arranged so that each preceding portion provides acoarser abrasive machining while each subsequent portion provides afiner abrasive machining, so that with a relative movement of theabrasive tool relative to the part first a portion of the toolconfigured for a coarser abrasive machining machines a part andthereafter a portion of the tool configured for a finer machiningprovides abrasive machining of the part.
 14. A tool as defined in claim13, wherein said portions the abrasive tool are formed as concentricportions extending around an axis of rotation of the abrasive tool. 15.A tool as defined in claim 13, wherein said portions of the abrasivetool are formed as abrasive disks which are very successively after oneanother in a direction of an axis of rotation of the abrasive tool. 16.A tool as defined in claim 13, wherein said abrasive tool has a workingsurface which is inclined at a predetermined angle.
 17. A tool asdefined in claim 16, wherein an axis of rotation of said abrasive toolis inclined at a predetermined angle, so that at least one part of aworking surface of an abrasive tool can extend substantially incorrespondence with a surface to be treated.
 18. A tool as defined inclaim 13, wherein the portions of the abrasive tool are integral withone another, so that the abrasive tool is formed as an integral tool.